1. Field
The following description relates to a bulk acoustic wave (BAW) apparatus.
2. Description of Related Art
Duplexers based on bulk acoustic wave (BAW) resonators are widely used in mobile communication systems. Duplexers have excellent performances, for example, low insertion loss, high isolation, and good stop-band attenuation, and may be integrated with a complementary metal-oxide-semiconductor (CMOS) circuit at a relatively low cost. In an example of a duplexer, a high-power signal may be applied to a transmission (TX) filter and, as a result, the TX filter may generate nonlinear output, for example, second harmonics and inter-modulation effects. However, the nonlinear output may not be allowed in a strict mobile communication standard, for example, a code division multiple access (CDMA) system.